In theory, yes. The plumbers attempted to extort from you more money than the job was worth and then threatened to leave the job undone unless you paid. Finally, they committed a tax fraud by getting paid in black. However, you stood up to them. Good for you. The problem is then how to prove this.
Send your questions for David Searl through lawyers Ubeda-Retana & Associates in Fuengirola at [email protected], or call 952 667 090.