Hi. I'm going to generalise here as an amateur. I'm not recommending you to miss any tablets. Stopping metformin would cause a small rise in blood sugar and you would lose it's small weight reducing capability; not a big problem in practice? If the Gliclazide is working well for you then you might see a big rise in blood sugar within a day if you stop it. Missing diabetes injections of any kind is not a good idea. It looks like you need to complain to your surgery as it appears to be failing badly. I order my prescriptions online using the surgeries online service and the meds are ready to pickup from my chosen local chemist 2-3 days later. I can order monthly prescriptions up to 1 week early so can and do build up a stock of 1-2 months supply to cover any problems. Is there anything you can do following a similar approach?