Hi there, my HtC chacha was low on memory and advised me to delete data, by mistake i deleted all media files which means photos and all sounds liek ring tomne/alarm and so on. is there anyway to retrive them or have i lost them for ever?

OK! Don't panic! Nowadays, the deleted files on a phone memory card are not actually destroyed immediately as we think. They are still there and become invisible. You do have chances to get them all back as long as they are not overwritten by anything new on the same phone memory card. So, you need to act carefully to get back your deleted files:
Firstly, Pick out the phone memory card immediately in case that any new file on it would overwrite your deleted files there.
Secondly, insert this phone memory card to a computer via a card Reader.
Thirdly, download a phone memory card data recovery freeware to restore all your deleted files back for free:
http://blog4mark.blogspot.com/2012/12/deleted-files-recovery.html
This data recovery freeware can deeply scan your phone memory card and easily get back all your wanted files back in the same way as it completely regained all the data of my friend back from this formatted Samsung phone.
If you are interested, you can download this phone memory card data recovery freeware here:
http://www.icare-recovery.com/free/samsung-galaxy-recovery.html

Fourthly, save and back up every restored file on another memory card or drive in case of data recovery failure.
Good luck!

Dont worry, you can still use htc data recovery program to recover deleted files from htc mobile phone, take a look at this guide
http://www.asoftech.com/articles/htc-photo-video-recovery.html

there are many free data and file recovery programs on the web
you could retreive themif you have not written or downloaded any and saved more to your hard drivehttp://majorgeeks.com/Free_File_Recovery_d6792.html
Free File Recovery is a small and easy to use application that will help you to restore files that have been accidentally deleted from your computer. This includes files emptied from the Recycle bin as well as images and other files that have been deleted by user errordigital cameramemory cards or MP3 players. It will even bring back files that have been deleted from your iPod, or by bugs, crashes and viruses!

http://majorgeeks.com/NTFS_Undelete_d5532.html
NTFS Undelete is free software that allows you to recover deleted files. It recovers files directly from hard drive, and it will work even if you empty Recycle Bin.
Before downloading NTFS Undelete, please consider the following:
When you delete a file, its content physically remains intact on the media, but the occupied space becomes marked as free. Next file saved to the disk may overwrite the contents of the deleted file.
It is very important to make sure that no application writes to the drive or partition where deleted file is located since every new file (even a small one) may overwrite the deleted file.


hope this helps you