Tax refund for retrospective marriage allowance claim

Good evening, my wife applied for marriage allowance retrospectively to the previous 4 years in December 2023. Only my taxcode was changed to S1383M (I'm self-employed). I have not received any calculations or tax refund. I contacted HMRC few months ago by phone, but I only received laconic information that they had to look into the matter and they would get back to me. Silence to this day.... When I check current or earlier Marriage Allowance claims,I only see this: Your Marriage Allowance claims: (Tax year / Status) 2023 to Present Active 2019 to 2020 Applied for Marriage Allowance retrospectively 2022 to 2023 Applied for Marriage Allowance retrospectively 2021 to 2022 Applied for Marriage Allowance retrospectively 2020 to 2021 Applied for Marriage Allowance retrospectively Any ideas on how to move things forward? Kind regards.

Hi,
If the previous years' transfer of allowances have been applied retrospectively but you haven't seen any overpayment generated, it could be that you weren't entitled
to receive the transfer - you may wish to check the marriage allowance eligibility criteria here Marriage Allowance.
You can also try resubmitting the returns for each year, as any transfer made should be automatically applied when the Self Assessment system generates your calculation for each year.
If you are entitled to the transfer and still don't see it reflected in your calculation, contact us by webchat or phone via Self Assessment: general enquiries , and we can advise you further.
Thank you.

Thank you for your answer. I don't really understand how I can resubmit the returns for each year, because everything was submitted by an accountant. I was unable to contact my accountant. I'm still waiting for a response. BTW I tried to contact HMRC by webchat but it's impossible, I have been getting the same message for several days: Our advisers are not available to discuss your query at the moment. You can ask another question, contact HMRC for more help (opens in a new tab) or end this chat. I thought it would be a simple matter if my self assessment is sent every year and everything is visible on the HMRC website.

Hi Elszu,
To review the back dated marriage allowance transfer we will need to access your record.
You will need to contact HMRC to review here:
Self Assessment: general enquiries
Thank you. 

Good afternoon, a few weeks ago I managed to contact someone via online chat and I was informed that my application from December 2023 arrived in May 2024 and it will be processed. Is it normal for it to take this long? I tried to contact someone via chat today but it was impossible: "Our advisers are not available to discuss your query at the moment". Kind regards.

Hi,
Unfortunately we are unable to review individual records on this forum. You can use this link to check on when you should expect a reply. 
Check when you can expect a reply from HMRC
If that date has past you will need to contact us by telephone or webchat: 
Income Tax: general enquiries
Thank you.