My opinion:
1. There are MANY different types of pensions, and I'm not sure what different types exist in your country.
2 You need to find a visa to enter Thailand, and then once you enter, you can get an extension of stay
3. To get a visa, you DO NOT need money in a Thai bank account. You do need to show the appropriate money in your local bank account.
4. The Thai embassy of London can be found at
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, they would know if you need to cash out your pension before you qualify for a Non-O/ Non-OA visa. I do not know if the Non-O visa is being sold, but I believe the Non-OA visa is currently sold.
I believe this answers your question. For details on how to enter Thailand (i.e. the Certificate of Entry, Insurance requirements, Quarantine requirements, etc) search Facebook for one of the many "Farangs Stranded Abroad" groups, they can answer the entry related questions.