Certificate of tax residence

I pay taxes in the UK, but have savings in banks in Poland and earn interest on them. Polish tax authorities require from me a certificate of tax residence and accept it for 1 year since it was issued. I applied for a certificate of tax residence on the HMRC website several times, sometimes successfully, sometimes not (I received letters of confirmation instead). Can you please provide me with a step-by-step instruction on how to fill in the form so I can receive a certificate of tax residence The form that I need to fill in when applying for the certificate is not suitable in my situation. I should not need to specify any income that would be covered by the certificate. I simply need a generic certificate of tax residency in both English/Polish languages. I do not understand why HMRC sends a letter of confirmation when I apply for a certificate of tax residence.

Would anyone be able to answer my question?

I would really appreciate if someone could look into this. I really don't want to contact HMRC via the complaints form, because I often receive a letter of confirmation instead of certificate of residence.

Hi,
Please refer to guidance at:
How to apply for a certificate of residence to claim tax relief abroad
Thank you