We had one last year and employed our own fitter.
Beautiful kitchen at a fair price but the salesman measured up wrong. Also they sent wrong units, cupboard door instead of dishwasher etc.
This resulted in extra work from our tradesman which they refused to cover.
You just get put on hold from their call center so we kept on at the branch. After they have got your money they don’t give hoot, couldn’t care less what mess they’ve made.
After a long wrangle we got our money back through the Ombudsman.
We look back now and laugh but at the time it was a very stressful and unplesant experience.
Sorry to be the bearer of bad news!