Need help passenger door won't open!

[mcdougc]

My B6 had a new steering lock and convenience module/ecu fitted last week, at the main dealer.

Straight away I noticed the passenger door would not open from the outside.
Rang VW straight away to book it back in, mentioning the issue was not there before.

They now claim the door motor and cable needs to be replaced at a cost of around £150.
They reckon it's a coincidence it failed on the same day the work was done, but it doesn't sound right to me.

Any advice from an expert?