Terrible service: Onsite Office Chair Repairs

We paid the deposit and the company picked up our chairs (12 Nov) for re-upholstery etc. Wonderful before-sales services. Supposedly 5 to 7 working days turnaround time.

Got e-mail after 7 days to apologise for the delay as a result of fabric provider delays. All well. Since then been e-mailing and phoning repeatedly for progress and estimated time of delivery. No response to e-mails. Phone when answered representative can not talk to me but will call back - never calls back. When not answered I leave a voice message yet more responses of "will definitely be contacting you before end of the day" without ever being contacted.

It is now already three weeks and some days later after the initial delivery date and no update or responses.

I would greatly appreciate any feedback as to when to expect our chairs.