Should I have discounted this bill?

Just come off the phone after a very difficult conversation with a customer who is convinced we were overcharging her.

We attended her rental property back in August and carried out a list of jobs for her (she was not present).

She has a clear recollection that our man, Morgan, called her at 2.30 in the afternoon and said he estimated he had another 30mins to go. So she thought he finished at about 3pm. Morgan's jobsheet records he finished at 4.55pm, two hours later than that.

She is convinced Morgan made a mistake on his jobsheet. We are convinced he left at 4.55. We think this, because:

(a) that is what he wrote on his jobsheet
(b) he remembers calling the customer mid-afternoon, but does not think he said he would be finished in half-an-hour
(c) he didn't do any other jobs that afternoon: if he really did finish at 3pm for sure we would have sent him on to another job
(d) he recalls being there till pretty much the end of the day

On the other hand, it is hard to understand why the customer can have such a clear recollection of this conversation about finishing in half-an-hour if that conversation didn't take place. My best guess is that conversation did take place, but Morgan just underestimated what else there was to do, or later on noticed some other tasks on the list, or whatever.

(Note that the customer does not think Morgan was fiddling his hours, she just thinks he made a mistake)

The situation is not helped by the fact that this all took place in August - the customer says she discussed all these issues a while back with someone else in our office, but whoever that was didn't note down the details of the conversation and / or didn't act on it, which is a bit of a cock-up, to be honest. Had we dealt with this whole issue a week after it happened I suspect it would have all been a lot easier.

Anyway, as I did in a similar situation which I posted about here, I stuck to my guns and insisted that we charge for the time which we firmly believed we spent there.

We had already discounted this bill for other reasons: (1) we had originally charged her 30mins for a visit which had to be aborted because the tenants would not let us do the work at the appointed time, we agreed to waive this charge; (2) she felt that because we had had the benefit of seeing the work during the original aborted visit we should have come with all materials ready for the second successful visit and not spent time fetching them during the second visit (we always charge for time taken to fetch materials, but we agreed to waive an hour of the second visit again as a goodwill gesture) (3) we bought a tin of paint which was the wrong colour (no argument there, we shouldn't have ever charged for that).

So, we had already discounted 1.5hrs off this bill, but the customer wanted another 2hrs off. I declined to offer this.

I am sure the customer will pay the revised bill, but she is convinced she has been hard done by and will no doubt be relating this tale to her friends. If you are that customer, and are reading this, please feel free to post your version of events as a comment and I will publish it.