You should have asked the agent, and the agent should have told you.

But to help you out : almost 100% sure that it was the non-o based on retirement. This is a 90 day visa.

After you get this visa and enter Thailand, you arrange certain requirements to get your 1 year extension which you can extend yearly. These 1 year periods are called extensions.

You can do this completely by yourself. Or you can use your agent for this 1 year extension. Price depends on factors such as whether you have the required amount of money, or you want to use the agent to "dodge" this requirement.

If the agent has to also arrange your original 90 days non-o retirement in Thailand, the extra work (which includes opening bank account by agent) will make it more costly.