Can someone collect debt for a service not rendered

My husband and I decided to hire Regus for a month. They gave us a contract that we signed under our company name. After the contract was signed they asked for company details etc under KYC including an electricity bill which we told them was not on the company name. They kept going back and forth and told us they can't do KYC unless the electric bill was given. Fed up with the bureaucracy we went to another co-working space instead and signed up. That very day we told them that we will not be going ahead with them via email. 10 days later we got an invoice that we ignored because it was system generated and we had already told them that we are not going ahead with them. A month later we get an email saying that we owe them the money for the invoice and that they have given our details to a debt collection agency. I researched on the net and saw that most reviews are complaining about the same unethical practices at Regus that we are experiencing with them. Can they claim money owed for a service they never provided because they could not complete the KYC? Their contract says we are liable no matter what the circumstances. What should we do as the next steps to protect ourselves and our company?