Can VAT be charged after a contract has been made for spectacles?

I went to an opticians had an eye test and agreed to have a pair of glasses at a total price of £220.  They asked for a £100 deposit which I gave using a credit card.  They will be ready in 10 days.  As I understand Contract Law.  A contract has been made here with offer, acceptance and the deposit as consideration.  No mention of VAT was made at any time.  Therefore, when I collect the glasses and pay the balance of £120 they cannot suddenly try to add VAT to the sum due because the contract was for £220.  Am I correct?

 

Thanks

Glynice

Alasdair Taylor's answer to Can VAT be charged after a contract has been made for spectacles? (697343718)

Certainly in the case of a B2C sale of a product, if an English law contract is made for a agree price, that price should usually be assumed to include VAT.

This is the case even where the sale is outside the scope of the Price Marking Order 2004 - for example, because the products which are supplied in the course of the provision of a service.

One issue here may be evidential. If you have any documentation specifying the price, that will certainly help.