Breach of contract

Once again I am finding myself being harassed by collection attorneys on behalf of Lancet Lab, when I have an agreement in place with Lancet that my account was to be paid every month and true to my word I have held up my end of the deal, I have been paying Lancet Lab without fail every month, in-fact before month end I pay you and mail you proof of payment. Instead of sending me updated statements you are sending debt collectors to harass and demand payment. Last year I had the same issue and you promised to sort it out, which was sorted out for a two months, again now it’s started, please Lancet Lab keep your end of the deal and stop sending debt collectors my way when I am still paying you in good faith!! Please do me a favor and don’t call me to apologize I don’t need your apology just fix this, and get these people to stop calling me!!!