Generally speaking, once fixed ownership of materials passes to the property owner so the Contractor (or their suppliers) cannot turn up and start removing things.
Any claim will be dependant on a number of items.
1. The terms of engagement of the PM and the scope of their instruction.
2. The specification against which the quotation was made.
3. The terms of engagement of the designer who put together the specification and the scope of their instruction.
3. The qualifications if any accompanying the quotation.
4. The reasons for the changes.
Although there is the possibility that this could be a con it is more likely to be genuine.
Sounds like you need to sit down with the PM and see where the extras have come from. Why they weren't identified in the quotation and who's responsible.
For example if the contractor has priced to install carpets and the spec asks for marble floors then the fault is with the contractor and they should bear the cost - or not carry out the work.
To put it another way. If you asked a contractor to 'refurbish my house' and this was the extent of the specification then you should bear the cost of the extras not allowed for.
There is always scope for misinterpretation.
If my posts can be interpreted in two ways, one that makes you feel angry and one that doesn't, I meant the latter.
Everyday is an opportunity to learn something new.