"Crisis point in local GP service"

We have a large village and lots of visitors regularly staying in the area with only one full time doctor at our local surgery. I am gravely concerned with the standard of care we are receiving as the one doctor we have seems to be struggling with the level of work. My father has prostate cancer which has been suppressed with quarterly injections over the last three years. His consultant stopped the injections as fathers PSA levels were very low. However he said if his bloods show a rise in his PSA to above 2.00, he will have to be referred back by the GP. A letter confirming this was sent to GP a month ago and it seems he still hasn't read it. My fathers PSA came back as 3.6 on the latest blood work and he was told that no further action was needed. Had my mother not asked what the level was, my father would be thinking all was ok until his next 6 months bloods. Clearly this is not good as his cancer could well have advanced drastically in that time. There were no warnings on his record to alert anyone. In my opinion excessive workload means our GP may be failing the local population and needs support.