When you say 'Part of a Clinic' do you mean a hospital clinic?
Firstly if you completely out or very low in test strips, you can do a couple of things...
If you've got a local A&E or small injury unit near you, pay them a visit explain your situation (no test strips) if you lucky if your meter is the same as they use, they might give you a pot to tie you over from their stock, or one of the doctors might write you a prescription.. If this isn't viable.
Contact your out of hours doctor, and explain the above either they will write a script out for you to collect from their base, or if you'll lucky they fax it straight through to the chemist for you! I
I've never had a problem with using either the above in an emergency (out of test strips, or running very low before I can get a new prescription from my doctor) the only hitch I had, was with out small injury unit, but that was because it was outside office hours, and it's out of hours doc who covers the unit out of hours, and he was out on a call! So advised to go via the main out of hours switch board
If you use the same chemist all the time, it's worth asking if they loan you a tub until your prescription is available!
But going back to your GP...
You do need to speak with your GP, but first check with your surgery who authorised the change to your prescription allocation... As this may have been done by the prescription manager and your GP may not be aware that it's been altered..
If this is the case, then it's likely a word with your GP and s/he will reinstate it.. If this is the case and it becomes a continuing problem, the prescription manager regularly reducing your allocation, then you then need to turn your attention to tackling the prescription manager to lay off..
If it's the case this is being authorised by your GP, then you will have to impress on s/he the importance of when you need to test, if you are on the MDI, then this means at least 5 times a day, you also require a surplus to cover hypo's, and if you drive you are required by the DVLA to test your BG before you get behind the wheel!
If you are under the hospital clinic, then speak to them as either your DSN or consultant will write a letter to your GP to instruct him to prescribe a certain amount etc... (you will find most consultants are more than happy to do this for you, most enjoy rattling the cages of the GP's)
Hopefully you get this sorted without having to fight a battle, but if you need info and/or advice about putting across your side of the argument, then just give a shout..