Paid too much tax but haven't received refund

I was on wrong tax code OT for a year and it was corrected to 1275L in March 2024, I called HMRC and my overpaid tax amount was calculated while I was on the phone, I was told the amount and was promised to receive a letter and refund but its now over 3 months and I haven't received any communication from HMRC. How long does it take to receive letter for refund as well as the refund itself?

Hi,
Issuing a refund by cheque can take up to 4 weeks.
To allow us to check on your refund and progress it for you, contact us by webchat or phone via Income Tax: general enquiries
Thank you.

Hey I claimed a refund for the PAYE tax refund but I choose the cheque option which will take 6 weeks to receive. is it possible to switch to the online bank transfer option once the claim request has already been made

Hi ROSHETHA,
Unfortunately, you can not request to have your repayment issued to a bank account once you have requested to have it issued as a cheque.
Thank you.