Galaxy S4 Clone MT6572 Help and Advice

[PausedDreams]

Hello everyone.
Before you read my post i suggest you arm yourselves with some pop corn/ tortilas/ chips/ because i will keep you here for a while.
I have searched for quite a long time and tried a couple of things which i found in the forum but didn't work before i ended up signing up and posting..i might have missed the right answer, so please forgive me if i did. Also i didn't know which is the correct section of my post because i don't know the brand of the phone.

A friend of mine accidentally bought a clone galaxy s4. (Phone info on first photo)
When he came to show it to me i could see that the phone was running really slowly and laggy (lot of fps drops even when sliding through the apps pages), and despite that he only managed to put just one application which was less than 500kb, he would constantly get the message of 'low storage' so he had to delete it to free up some space. I checked his storage through phone settings and he had total space 16GB and from these, 13GB would be used up by apps but since he hasn't downloaded so many apps yet it seemed illogical. Same goes with the phone storage, 16.53 GB total space and despite this it would show that he has used up a lot of it on apps pictures videos etc. We hadn't taken any photos yet so it is again weird. Please have a look at the second and third screenshots. (i also put a 4gb sd card which was almost empty, and it would show that i inserted a 16gb sd card which had about 2 gb free memory :/ )

So i offered to try to format the memory and do a factory reset. I did it since i had some experience with my galaxy s2 which is original.
Guess what, it would show the same storage as if i never touched it, run really slow, PLUS 23 hours a day there is no signal and can't make any phone calls. And even if there is little signal once i try to make a phone call the signal gets lost.

I have managed to download cpu z and hardware info and as you can see from the rest of the screenshots the actual storage is 137 MB internal and 12 MB (!) external.

What is going on exactly with this phone? How can i make the phone run faster and not so annoyingly slow and laggy? How can i get the signal back to normal? And is there a way to make the memory be 16GB for real? Maybe this firmware is 'masking' the phone's true memory capacity? Or is it really just 137MB and there is no way to expand it's capacity? Maybe a root or some new firmware? The only experience i have with rooting is with my original galaxy s2 so if there is such a solution please tell me in detail the procedure as i suppose it would be different from original phones. Looking forward for your replies. Thank you for walking with me so far.

[NexusTrix]

looks like your friend got a crap clone. with very low storage and RAM. It will be not easy to get it to working well with that low memory and storage.

was the phone making phone calls fine before you formatted it?

and what you mean you format? how did you format?

[PausedDreams]

Thank you for your reply.

Yes it was making calls normally before format.

By format i mean I did 'erase phone storage' through settings, and when i saw this didn't work i also did hard reset with the 3 button combination and i did wipe data/factory reset.

It would be good to confirm that it really is just a crappy phone and it is just not worth my time bothering or if there is any hope to do something.