Client has changed everything without my knowledge

I have a client that I run book-keeping on Xero for - all the record-keeping is done by us at their premises.

Today I go in and the client tells me that we're not using Xero anymore, he has been out and bought Sage Accounts Professional for over a grand because it's cheaper than Xero and it does job costing so will save us time.

Not only that but the client has entered the debtors and creditors himself - it may be a mess, it may not be - but he has spent most of the time on the Sage Support line today.

To say I feel pushed out is an understatement - but I really don't know how I should react - does anyone have any thoughts?