How to unlock your DB2020 phones CID 49 and CID 51 without server credits?
Start DB2020 inside software v3.4 or higher version
Select phone model
Press phone info to see which CID your phone has
If the phone info is:
CID in FLASH(dec):49
CID in FLASH(dec):51
Then add to software "UpgradeCID49_CID51_to_CID52.ee" file
The file is found in: C:\Program Files\GriffinTeam\MT SonyEricsson\DB2020 inside\Repair files\
Press Do IT button and wait to software finish
Disconnect phone from cable and remove battery
Attach battery and power on the phone
Wait to see message "Insert sim"
Power of the phone and connect it to cable
Press phone info to see its phone CID in FLASH(dec):52
If yes now you can use CID 52 unlock method which also does not require server credits