Reebok Easy Tone trainers - has anyone had any problems with them?

[101handbags]

I have been wearing my Reebok Easy Tone trainers since last September. At first I was really really pleased with them and I could notice a difference to my calves and especially my bum. I do walk a fair amount, about 20 miles a week, and I walk quite fast. The trainers have air-filled balance pods on the soles and one of these pods has now ripped and burst and both soles have tears in them. I am very tempted to return them (I bought them from a well known catalogue so I have proof of purchase). They cost £75 and I was rather hoping they would last longer than 5 months. They were advertised as particularly suitable for walking. I was just interested to know if anyone else had had a similar experience of the pods bursting/soles ripping. And would you return them? I suppose I have nothing to lose as I can return them for free and I would be throwing them away anyway, even if they tell me this is 'normal wear and tear'. Thanks very much.