No Acceleration - Intermittent Fault

My PEUGEOT 206 XS 1.4 HDI 70 developed a potentially lethal intermittent fault. The accelerator failed and the car remained/reverted to ticking over. This happened when moving from stationery at junctions, traffic lights etc, but also in the motorway fast lane. The fault was investigated by Peugeot workshop but no fault found as it is intermittent and the computer can only detect it when it happens. The solution offered by Autos Marcos, Torrevieja, Spain, was to leave the car in the workshop for a week and it would be tested daily. No courtesy car would be provided and there would be a cost for the tests. This is a ridiculous solution as:
1. The fault may not happen during several months of daily useage, so the fault is unlikely to arise during a week of daily testing. Even then, no doubt, the test would be carried out without the computer, the computer would be attached and the fault would have corrected itself.
2. The same number of tests could be carried out in half an hour continual testing as a week of daily testing, so why lose the car for a week for the same number of tests.
3. I know what the problem is, why can this not be converted to Peugeot engineering?
The attitude of the workshop was that the problem is mine and they have offered their solution. Peugeot Madrid and Peugeot France took no interest, and all were content to let me loose on the highway with their product with a serious fault. Disgraceful Autos Marcos and Peugeot.