How to stop my iPhone 4 from pausing music?

How do I stop my iPhone 4 from pausing music?

Added (1). My iPhone 4 keeps pausing music and the sound control disappears. It does this with headphones, aux cords, and when its playing through the speakers. It keeps the music app open, just pauses music.

IPhone 5c battery issues after jailbreak?

So a few months ago I jailbroke my phone, and since then I have experienced really bad batter drain. I will gladly pay the money for a replacement battery if that will solve the problem, but I was wondering if it will.

These are my battery statistics:

Design Capacity: 1500 mAh
Max Capacity: 1400 mAh (this number fluctuates, sometimes going as low as 1350 mAh)

If someone could tell me whether I need to buy a replacement battery or reverse the jailbreak/restore the phone, it'd be greatly appreciated!

Would I be cheaper buying lots of singles from iTunes or a portable CD player and a bunch of CDs?

I don't really like whole albums of songs and on iTunes they are so expensive about £1.00 per song and there's so many I want!
I need them for work next week as I work very long hours and often the radio is turned off at Christmas time for being "offensive"
Should I purchase a cheap player and lots of CD's? Or should I buy lots of loose songs and put them on my iPhone?

I don't have much money at the moment.

Ebay fees how much will I get?

Ok I sold an iphone 5s for £358 what fees will eat into this in both paypal and ebay? And on another note how long should I keep the money so to be sure the buyer will not make a claim if he decides he wants his money back and returns the phone. I have to pay my brother as it was his phone I was selling.

A few years ago I sold a camera the buyer wanted to get a refund and at the time I had no money in paypal and a credit agency started to harass me for months every day trying to get the money. I don't want this to happen again.

Added (1). I sold iphone on the 11th /11/14

Added (2). Just wanted to point out he has given me good feedback should I still keep the funds? I have no refunds on my listings but you know ebay is a law to themselves. And they do what they want half the time.