Conditioner. Thats what i use when the dogs get mats. just a dab and start at the " end" of the mat and try to separate the hair from there. Work up into it. if you start at the top you will get no where : /. It takes some time but it ends up working.
also you said digi is scared of the brush? Our old shorthair was terrified but it helped to use a soft brush on her to help get burs off of the coat. It hurts to bad to take them of with fingers and obviously they had to come out! I would leave the brush out with her, just in the room and she after a while would warm up to it. once she looked and took a step closer to try and investigate it went back away. every day she would be more and more interested in it because, well once she looked at it, we took it away! She started to walk up and sniff it finally and then she was okay. except when we picked it up again, she tucked her tail under and looked at us like it was death haha. then we just started carrying it around. ours had a little tie at the end that i could wrap around my wrist, just started wearing it. that took about 2 weeks (ugh! haha) she warmed up to it and then we started holding it in our hand and just petting her ( petting her with the opposite hand, with brush in her sight still). slowly we could start petting her with the brush Cupping it in our hand like it was mine. Not sure How scared of the brush digi is but hey anything that doesnt make them scared is good.
Glad the mat is out : ) good luck for next time!