What if I cannot get a charging company to respond to me dispute?

[OOS]

I hope this is in the right spot.

I recently left Thumbtack-a marketing by the lead company. I had tried in the past to get someone to respond to me before I left. Now that I deactivated my account, I doubt I will get a response at all. How do I dispute a charge if I cannot get someone to respond?

I'm not sure I will be charged, but there is always a chance. I don't want to lock my card because I need it to conduct business. 

I thought Thumbtack was a great company until I discovered they charged me over $100 for almost every lead. I still have some leads that signed and booked with me to perform a wedding. I don't know if Thumbtack will charge me once the weddings are complete or not. I'm just hedging my bets and covering my bases, so I know what to do.

[Minion]

Hi @OOS 

What form of payment did you use to setup payments to Thumbtack in the beginning.  I would think you should be able to call your bank/credit card company and let them know that payments to company X are not authorized to process a payment from you and they should be able to stop all payments to them.