gorenje warranty

iv sold quite a few of these machines without much trouble so far, they come with a two years guarantee however one has failed bearings at only seven months use the customer informed me that the repair co. based in leeds took three weeks to obtain spares and then took the machine in to fit them saying it was a difficult job and would not give a time for completion. as you can imagine they are not happy. and have contacted gorenje directly who suggested they could get a replacement via ourselves,
i am not sure what to do, but will try contacting our supplier (dad ) for their input
as the machine is in for repair i have suggested we may be able to supply the customer with a loan machine
how should i proceed ?
i am also concerned that future warranty calls may be unsatisfactory and may choose not to supply these machines in future
i realize this may be a one off
but am concerned