Is this;
a. An OP who came to live here from a different country who has been subjected to racism because they speak with an accent from their country of origin (however slight)?
b. An OP as above (or who has been here for years/since childhood/birth) who has been subjected to racism because somebody has assumed they will be speaking with an accent from another country/a home language when they don't or, if they do, it will be only slightly different to the local accent - or more like RP?
c. An OP who, irrespective of ethnicity or place of origin, speaks in local dialect/has a strong local accent that somebody finds unintelligible?
d. An OP who is neither of the first two categories, but speaks really quickly?
e. An OP whose speech doesn't always follow official rules of 'proper' English in terms of grammar, tense or syntax (eg, 'I ain't got no...')?
f. An OP who was speaking about very technical matters they have specialist knowledge about or using Corporate Speak to somebody who hasn't ever encountered them (or thinks they're bollocks in the case of the latter) who was answered with a 'Could you try speaking in English, please?'
g. I have a stammer; as a child, I would speak very quickly when not tripping over the words. The phrase I thought of when I read the OP was 'For Heaven's sake, SPEAK ENGLISH, CHILD' because it was what was barked at me every day, along with 'STOP GABBLING, this is you OODAGOOGOGOOOGOOBOOABOOLA...'.
If it's anything other than f., we can safely say that the person who spoke to the OP was being a complete dickhead (as Corporate Speak, like Art Speak, are definitely Not English even when using ostensibly English words).
But for ease of communication online where posters might not be able to decode the meaning of a post, it might help to know which category of a - g she falls under.