"Professionals need to listen"

I'm Post bariatric surgery, so in order to stay well i have particular vitamin and mineral supplements. I initially tried to book my b12 injection and was told I needed a loading dose, I was surprised but double checked this was nessassary, which I was told it wasn't needed. So I contacted the surgery again and was told this was the guidelines. Clearly the surgery have not been keeping abreast of the guidelines for post bariatric surgery patients as they continued to insist they were correct, but eventually did agree to just give me the normal dose. The b12 injection also needs to be given every 12 weeks so I booked it in only to arrive and be told I couldn't have it for another 2 weeks. I again spoke to my dietician who rang the surgery and was told I'd only had it 8 weeks before, which was wrong. Its taken several calls and a long time waiting for the phone to be answered before finally getting another appointment to have my b12. The reception staff are very nice and helpful but the professionals need to have a better understanding when it comes to the needs of post bariatric surgery patients and also LISTEN instead of assuming they know best. It has lead to stress and a lot of time wasted.