T-Mobile: lousy 4G data service iN SF and IN Silicon Valley !!

Have tried 2G,4zG, and 5G rate plans, but just  S  L  O  W .
Page loading takes F O R E V E R !! 30-60-90 seconds !?
The CSRs and Techs are 98% honest and helpful and SO POLITE.   Only a few time wasting BS-ers that need retraining.
You will get very little tech help in the sell, sell, sell Stores, not even a phone security app , and maybe only your contacts transferred.  Suggest you jeep all your phone contacts on Hotmail/Gmail and do not let T-Mobile touch/move them!! Every time in 3 years they have lost contacts and contaminated mine with duplications/6 copies !! Pathetic. 
Have one expert tech /store.
And I am sooo tired of that same horrid onhold tune.
Have Samsung SG3 and is nigh impossible to quickly retrieve last e-mail put in trash.
Page Before , in lower right, is also too slow or just impossible.
Took over 30minutes to talk to Manila customer service last time; No call-back option !!
When will we customers see any significant improvement ?!
Best fitting power cord is the Samsung for Samsung SG3.
Also $30 two-three day back case battery by Anker is Wonderful, no daily recharging.