I preassume that your device is rooted and your sdcard data is backed up.I think,the mount script didn't work because of inappropriate attributes.
.Ok heres,how i installed Link2sd...
1.First of all download and install MiniTool Partition Wizard in your windows PC.
Connect your handset to the PC via USB.
2.Launch MiniTool Partition,you should see your SDcard mentioned in the list Under Disk 2 probably.
3.Right click your SDcard mentioned in the list, press "Move/Resize Partition"
4.In the Partition size,allocate bigger chunk of partition for primary partition.This is the partition your phone will access for general purpose.Say you allocate 7GB from your 8GB memory card.
5.Now Under disk 2. you will see and unpartitioned space of about 1GB.This partition will be used by link2sd.You may allocate your sdcard as you may wish.
6.Right click the upartitioned space to create a new partition under "Create As".If a warning popup asks for permission click YES.
7.Under New window Create As,choose "Primary".For File System type choose 'FAT32'.though you may choose among ext3 or ext4,either is supported by link2sd.NTFS is not supported by Link2sd or android OS.For partition size take whole unallocated space.Click on OK
8.Click Apply button<upper left corner in the screen>.
9.Restart your phone.
Again use your Link2sd app to create mount script.Now your app should work fine.
Don't forget to hit THANKS if i helped you.