from your modem screenshoots, if refer to Down/Upstream SNR Margin, it's OK & can support 4Mbps package, because my modem SNR Margin for Down/Up is about 33/25 and currently i'm using 4Mbps package without any disconnection/speed problem.

BUT if refer to your ADSL Mode = G.DMT = don't support 4Mbps line. TM need upgrade to ADSL2+, if you saw at modem status Mode = ADSL2+, you can register streamyx 4Mbps.
BUT for double check, just call 100 @ ask at TMPoint counter.
1.easy way - call 100
2.or go nearer TM point, ask at the counter, they will check your current streamyx phone number
3.easy if you know "how to" - enter modem management, check modem DSL status @ DSL statistics, if your find your DSL mode = ADSL2+, YES your area coverage with 4Mbps package

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this is my speedtest.......... 

You can call the 100 / installer but your chances to success would be very minimal as they will based on a few external factors such as you are not getting 70% of your desired speed then the adjustment of the downstream / upstream is possible.

Thanks

If you increasing your cap to 5024 kbps then most likely your speed will be increased but ping time to websites will remain the same. How much are you getting under 4Mbps plan?

2day speedtest

You don't need to call 100 / Installer because normally they would tell you the same thing or ask you to contact the installer. 48 hours to get a full speed is a normal procedure as far as I recalled.

Just bear with them for another 2 days and I'm sure you will see the difference of your speed.

Thanks

Please provide the date & time you request to upgrade your plan to 4MB and when did the installer came over to appoint you?