SMS on MY PC

I use to be able to send SMS messages to many T-Mobile Chats. Nothing too big, usually way under 1MB. Then last year it stopped. I contacted T-Mobile and go the "Third Party" excuse. We spent about 2 hours trouble shooting. I had previously contacted COX and they were having no issues. I tried sending from various PCs to my iPhone, nothing. Then POOF it all started working again from my default email Outlook, and all was good, it went down again, and another 2 hours and back up. It has now been down for about a month and NO ONE from T-Mobile staff will answer with a solution I even sent a hard letter with dates and times that T-Mobile was trouble shooting, NEVER heard word one from the executives. I am about a week away from dumbing T-Mobile and go back to Verizon that I know works. T-Mobile just doesn't care and I am just one customer, won't be missed and easily replaced.

This is what I last sent: 

I have spent multiple hours with COX, Microsoft, and T-Mobile and all are pushing the issue troubles to Apple. I was on the phone with Apple today trouble shooting my iPhone to no avail. Yesterday Marcus Watley tried many things and the end result was "Sorry not a T-Mobile issue" and they closed the ticket. Microsoft revienosotrosd my PC to ensure all the settings were correct and Outlook was up to date and functioning.

The last ones I talked to was Apple, and they turned it back on the carrier, T-Mobile. The tech explained it simply. "PC to SMS text is a carriers addition as to what they provide. Just like Verizon provides as well at AT&T. Apple has zero control over PC to SMS Text as it is a carrier function." That makes sense to me.

So it appears that T-Mobile gives instructions on the Internet as to how to perform this function. I have been doing it for years and it stopped working so there is an issue and all roads lead to T-Mobile.

Will my new carrier be better? I have no clue but hope so. In any case we will be switching here soon as soon as I am done with my research and reviews from friends that have various carriers.

I am but one customer that won't be missed and easily replaced. I thought I had made a good decision but when a usable issue doesn't work and there is only blame to others, it is time to leave.

Thanks for your help, but I have to do what I have to do.