Difficulty getting madopar?

we have a gp practice which dispenses our drugs (rural area). We keep getting told that Madopar is difficult to get and sometimes have to wait till it "comes in" or, like today, I have to get in car and go to 8 miles to nearest town taking a prescription to get it from a pharmacy which assures me there is no problem with getting this drug, it is readily available. Does anyone know what is going on here? The gp pharmacy assistant says it is because our GP contracts to Boots and "their patients have first call" on Madopar. Can this be true? Good job I have a car and can drive it to get the drug (for my husband).
I live on the edge of Cambridge,and the week before Christmas I could not get my Madopar CR from the chemist I always use, I phoned other Chemists and found one with the quantity I needed. I do not drive so had to get a Taxi to from the other Chemist £28 expensive yes but if I did not have my medication I would not have had a Christmas. this has happened to my mother who takes other medication. and it is confusing being given different makes of tablets that look totally different colour and size wise. As has happened with my Blood pressure tablets.
If you collect a prescription for your meds. from your Gp,or wherever for that matter . If you ask whoever does the prescription for you to make the prescription to say the drugs you receive must be generically the same to the ones you normally take,this should solve your problem. It might be a different size,shape or colour, but
if it is generically the same,this means that although the size, shape, colour ,or,name may be different ,in the same amounts. the actual tablet contains exactly the same ingredients,