What's this bank payment?

[PeanutButterLips]

Can anybody shed some light on what's happened to my bank account today.
I have been paid my monthly wage and filled in a pay query at work due to not being paid the full amount of hours I have done.
However, I checked online banking 30 mins ago and have had money put in my bank.
It is coming up as PCM55CI and then a lot of numbers, also coming up as a CHAPS/international payment.
I rang work but payroll line was engaged so waiting for a call back but if it isn't my work who could it be?
I will ring my bank if it isn't work who paid into account. My usual pay from work comes up with the name of company as the reference.
I bank with Natwest.
Anyone else experienced this? If it's not work I can't think who the money's come from as I'm not expecting it.
Thanks

If your company has made a same day payment this could be a CHAPS payment. Sounds likely it's work putting in an additional payment.

IS the amount you received roughly the amount you were owed by your work?

Work rang back it is a payment from them. But it's still not the full amount which is why I was confused.
So will need to speak to them again regarding the rest.
Thanks