Absa idirects dishonesty

My access is 3k as far as i know.I put in a claim and I was told my access went up to 4k and it was changed the day before my claim.I asked them why was I not informed about the increase in my access and I was told that they sent me a letter but they can't tell me how the letter was sent cause it was not via an email or post. They failed to tell me how the letter was sent and yet they made changes on my policy without informing me as their client. No letter or any communication was sent. When I called them I was told my access is 3k and now I get an sms saying my claim as been approved with an access of 4k which I think it's not fair to make changes on a client's policy and not inform them.