Incorrect billing - Consumer Complaint for Flow Jamaica

I attended the May Pen outlet on 23. 11.2020 to sign up for the Do It All bundle, the customer service agent advised that an engineer would be along on Friday 27th to carry out the installation... Fast forward to 3rd December, this was the date the engineer arrived, installed everything bar the WiFi extender... I went to the May Pen outlet on Friday 11th Dec first to ascertain when I can expect to have the WiFi extender installed and 2nd to get the account number and information on payment date for my newly installed bundle... The customer service agent told me that the bill was due to be paid on the 9th of every month.... I then asked her if this meant my payment was overdue? To which she responded, billing is the 9th of every month. I then asked her how much was it, me thinking from the 3rd of Dec to the 9th was only 7 days, plus the fact that I had signed up for the Do It All bundle at the promotional price advertised on the Flow website, which runs until the 31st Dec 2020...So you can imagine my shock when the May Pen agent told me my bill was $15,000.00+ I explained to her about the promotional bundle on your website, which fell on deaf ears. Anyway to avoid disconnection, I made a payment of $7,500.00, now on the 15th December my FIRST bill was sent to me via email, you can imagine my shock at seeing the sun of $15,685.06 for my first bill.... After numerous attempts to contact Flow via telephone, I finally got thru to 4 different agents on 21st December 2020..The 4th agent informed me that my bill was that amount to take into account the previous months service charges.... Flow have on account that I had the Do It All bundle installed on the 24th November!!! They were due to arrive on the 27th to install but didn't turn up until the 3rd December and that is only because I was persistent with telephone calls, and showing up in person at the May Pen outlet.. I also informed the customer agent that we are Still in December therefore the Do it all promotion bundle still applies and my account needs to be adjusted to reflect this. The agent out me on hold, then came back after 15 minutes to inform me that she needed to go thru the account to rectify the error and would call me back once she had completed it. I asked her twice if she would be calling me back today (Monday) twice she told me YES... It is now Tuesday 22nd December 2020 and still no response from Flow. I cannot begin to tell you how frustrating it is dealing with this company. It is pointless employing people who lack the skills or knowledge to deal with your customers' queries... The least Flow could do is to ensure staff are properly trained and attend refresher training Regularly plus customer care training on HOW TO TALK TO People.... They are not on the road with their compadre's..... I would like to add that when dealing with customer service agents on the telephone I have found them to be very courteous and mannersable, even if they are not able to help me. Aside from one agent who out the phone down on me and I know I wasn't rude as this is not how I conduct myself.