Some years ago, my surgery was regularly messing up my prescription - missing out items, prescribing my basal insulin when I requested the bolus, ordering everything when I only asked for test strips and lancets, ... - as a result, I wrote an "evidence-based" letter to the surgery manager. As a consequence, they changed their process to include education and check for all diabetes prescriptions and have not made a mistake since.
Whilst I do not want to defend such mistakes, I believe prescriptions for diabetes supplies are different to many as we do request all items on the prescription at the same time: typically someone takes the same dose every day and the tablets can be allocated to last for a set period. The people in the surgery have to educated about this.
The moral of this is don't put up with the mistakes, write a polite but firm letter/email to your surgery manager explaining what happened, the consequence to you (loosing 2 hours work) and the potential risk if they get it wrong again (unable to take your medication which keeps you alive). Unless they know they have a problem, they cannot fix it and after running around to solve the immediate problem, they will move on to the next one and forget this mistake.