Concern Over GlucoMen Blood Tests - Giving High Results

Earlier this year I was issued with a GlucoMen blood testing kit (manufactured by Menorini) by my local medical practice.
This was to replace a Bayer Contour blood testing kit.
I was informed that the local Health Authority were switching to the Glucomen kits (in the interests of economy).
Immediately on using the Glucomen kit I found that blood sugar readings were higher than expected.
After expressing my concern to my local medical practice, I was asked to compare test results using both the GlucMen and Contour test kits.
This I did over a period of several weeks, and meticulously recorded the two sets of results.
The result was that the GlucoMen kit gave results that were consistently 20% higher than the Bayer Contour kit.
Additionally, some of the GlucoMen readings were ludicrously high.
I reported this in detail to my local medical practice, who returned the Glucomen kit to Menorini, with a covering letter.
When I enquired of the practice as to what Memorini findings were about the results and the returned test kit, I was informed that Memorini had replied they HAD NEVER RECEIVED the letter or kit.
This, of course, may be a neat way of Menorini not wanting to have anything further to do with the "complaint".
So we are now back to square one. Or square -1, as I don't have the use of any test kit at the moment.
My local medical practice is no further forward in finding out anything as regards the reliability of Memorini GlucoMen test kits.
They have been issued to a number of patients in the area, and, at the moment, there is no feedback as to whether these kits can be relied upon, - OR NOT.
Does anybody else have any experience as regards Menorini Glucomen test kits which might support my concerns?

I'm confident that the local medical practice DID send the test kit to Menorini. I have spoken to the Chief Pharmacist at the practice and she isn't a happy bunny at the moment regarding this business.

The kit that I was supplied with was probably the Glucomen GM. I say, probably, as returned the whole lot to the medical practice (box, test strips, needles - the lot) and am only going by what I recognise on the Glucomen website.
Some of the readings I obtained were so ridiculous that I would hate to have to rely on it for, say, injecting insulin.
As far as I am concerned, the kit that I was issued with wasn't much better than a toy.

Many thanks for the above comments. I shall let my local medical practice see them.
As regards returning the kit, I don't believe that there is any risk of blood contamination on the kit. However, I am only a layman in this respect.