As has been indicated above, the probability of a successful data recovery in this case is low without the help of specialists.
To begin with, do not use that hard drive until you have found a way to deal with the partitions/files. Otherwise there is an immediate risk that anything recoverable becomes overwritten.
Professionals avoid working with the original hard drive at all. Instead, the hard disk is cloned (copied sector by sector) to another drive. Recovery attempts are made using the copy.
Recovery programs for Mac can be found, for example,
here. You will have to investigate whether a certain Mac utility would be in a position to handle PC partitions and file systems (I guess that a good program should see anything written onto a disk; whether it can make use of that information is another matter).
Basically, it ought to be possible to try the data recovery on a PC, too. The same should apply here; a PC program might see the data bits, but would it be able to handle a Macintosh file system (and thus make something useful out of what it has found)? Check with the program supplier.
Anyway, do not reformat/repartition again. That is most certainly only going to make things worse.
Jan