I would follow your complaint up with a written complaint. As pp have advised state you have already made a formal complaint and that you are writing to accompany that. Advise of the situation from the beginning so for example I would write along the lines of:
16 January 2020: took out insurance policy (no ) for Mr Cruz as the main policy holder with a full driving licence, Mrs Crus as a named driver with a provisional driving licence. Plead see attached statement of facts for further confirmation of the policy taken.
23 September 2020: Mrs Cruz suffered a seizure.
26 September 2020: Mrs Cruz was notified by her doctor that she should no longer drive. Mrs Cruz contacted the DVLA who have stated she must surrender her licence due to her medical issue.
29 September 2020: Mr Cruz contacted Insurance Co at 15:46 and spoke to Amy in customer services to advise that Mrs Cruz had now surrendered her licence for medical reasons and requested her removal from the policy. Amy advised that the policy would be cancelled, that a £* cancellation charge would apply and a £* set up fee would apply. Amy also stated that Mr Cruz would need to declare that he has had an insurance policy cancelled to any future insurers.
30 September 2020: received an email further confirming the information that Amy had given in the call on 29 September 2020, please find this email enclosed.
2 October 2020: New insurance policy taken out with New Insurer, as you advised was required, Mr Cruz disclosed that he has had an insurance policy cancelled. He has been charged £* for this policy, compared to the £ charge expected if he did not declare a cancellation. I have confirmed with the insurers that any changes to the policy such as amended the information about the cancellation should this be revoked and recalculating with the 5 years no claims bonus added would be in the region of £*.
Clearly there has been an error made in this process as we have not provided false or fraudulent information at any point during this process. I would like to note that I am a vunerable customer due to my medical issues, of which you are aware.
We would like to be compensated to cover the entirety of the costs we have beared and compensation for the time and distress caused by this error.
Both sign and date the letter.
I work in financial services, not the insurance sector but customer service is generally similar in the regulated services and we both go to the FOS. Our process is that a customer service advisor will initially take notes of the complaint, a complaint handler will then pick up the complaint and investigate it. Sending a letter stating all of the facts for when the complaint handler reviews it can help things get resolved quickly and efficiently. If you call up and have a less experienced customer service advisor and if you're feeling a little fraught then a situation can quickly escalate where no-one knows what is going on, what the other is saying and nothing gets resolved. If you do call at any time ask to speak to either a manager or a complaints handler. Demanding to speak to the Head of a call centre or the CEO will do nothing to help the situation (I know you haven't said this but I think I read it from a PP), all it means is your call will be pushed back as much as it can be within SLA as no one wants to speak to you. Much easier to catch flies with honey, I'll speak to colleagues and say Mrs Smith is lovely and she has a point, that call back will then be picked up first. If I say Mrs Smith is going mad, she won't listen to a word I say and keeps shouting at me, well that call is happening right at the end of the day and if it Mrs Smith doesn't answer tough luck.
Sorry for the long response, hopefully they'll get back to you soon. I wouldn't expect it to take them the whole 8 weeks.