When I direct the firm to that Consumer Ombudsman website which says they have to stick to agreed estimates, they even disputed that website saying "it's not the law".
Its lawful to contact the consumer adviser.Price disputes require proof
If no prior agreement exists regarding the price, the consumer must generally pay the price charged by the contractor, assuming the price is not unreasonable and the invoice is itemised.
Hourly rates must be based on actual working hours and necessary travel hours
Cost estimates must generally be stuck to. If the final price is lower than the cost estimate, the contractor is not entitled to charge according to the original price estimate. The price estimate may only be exceeded by 15% and justifiable grounds must be given for this
A fixed price , i.e. a piecework rate may not be exceeded at all. Nor does the contractor have to lower the price even if the work turns out to be cheaper than expected
Maximum price is the upper limit for the price. It may not be exceeded even if the actual costs of the work are greater than expected. The price may, however, be lowered according to the amount of work performed or materials used
In the event of a dispute, the burden of proof regarding the agreed price lies with the contractor. At least in renovation contracts worth EUR 10,000 or more, the contractor should ensure that the renovation agreement is prepared in writing.
If you disagree with a contractor regarding an invoice, you have the right to withhold payment of the excess portion invoiced. In this case, you must always submit a written request, along with relevant justification, to the contractor to have the price adjusted.
If the contractor does not accept the adjustment and insists on sticking to the original invoice, you should contact a consumer advisor immediately. The consumer adviser may assess whether there is reason to continue withholding payment and dispute the matter.
Asking for the proof of the qualified workers used to fulfill the original estimates time and quality is another way to add pressure.Its an unreasonable request to charge a higher than agreed estimate if the contractor uses low qualified workers.