[Galaxy Ace S5830i Q&A, Help & Troubleshooting] ehsanotaku:
First of all do please explain all of the instruction(s) you did take from step one , rather than directing us to some general external links method .

Your custom rom comes pre-rooted with su app as i gathered and binary update installed , so i didn't get the part about installing stuff and please clarify the process you went through for play store an Gapps installation as com.android.vending-5.2.13-80321300-minAPI9.apk was omitted from system/app of your TWR v2.5 . ( post #270 my comment )

If you got any root explorer installed please give me what you see under /system/etc/init.d folder of your device ( you can also install terminal emulator and give me the following output command is generated >> "ls -l etc/init* " & type "su" to get elevated and then type " df" for now and FYI there are two method for increasing your internal space : 1-link2sd free version from play store and 2'; universal script method which is a bit complicated but does not require app linking method such as link2sd app .

On the side note though , If I am not mistaken TWR v 2.5 is heavily customized , therefore few MB of space will be remained under /System partition . You need to re-partition your external device through clock work mod and install link2sd app from play store to increase internal memory space , or use cronmod script which is a bit complicated . ( upon re-partitioning , all of your external SD card data will be erased , so back up your critical data ) . I need those output i requested to be any assistance to your cause , but this is a general guideline anyway :

Link2sd instructions :

1- Uninstall any new app you have downloaded through your built -in application manager or from play store/my app section ( before that unlinked then through link2sd , if you created link2sd connections ) . Delete any .apk file leftover within your Download folder , accessible through your built-in file manager ( root explorer /es file explorer will do).

2. assuming you are familiar with your custom recovery console ( a.k.a : CWM ) , turn off your phone and push the hardware combo key to get to your CWM :

3. Go to advanced>partition SD card>choose size ( 1024mb)

4. After that( ext4 or ext2 will be created upon entering 1024 Value , depend oc the CWM version and kernel you are using ), then choose 0mb as swap partition and continue .

5. After this is done go to mount and storage and format sd-ext there (back up your sensitive data as you will loose them ).

6, Reboot your device .

7. open up your internet browser and search for " free link2sd app from play store " , if you can't find it directly over play store search function and install the app.

8. Open up the app , you will asked to choose your sd-ext partition format : pick ext4 or ext2 ; if you got any script error , then from top left corner menu , choose recreate mount script and pick ext2 , if ext4 generated mount error .

9. from top right corner menu , choose multi-select > push on the option on toolbar or select your apps > push on three vertical dots from top right again and this time choose link to sd card > all of the app selected by link2sd or hand picked by you will be transferred to /sd-ext partition plus some other technical stuff .

10. now back to the first page and from top left menu , choose storage info : you must see something like :

Internal

SD card

SD Card 2nd part

System

Cache

spaces , from now on , your limited internal will remain at the fixed ratio and your /mnt/sdcard and /data/sdext2/4 will be involved with apk data and library and app cache

Soft rebooted from top left corner menu of link2sd in order to become effective .