Does a rehash count as a sequel?

I am referring to the film 102 dalmations from walt disney pictures. I had seen 101 dalmations before and found it great. Hoping to have a similar viewing experience, I went and rented out the 102 dalmations. Guess what? 102 Dalmations is a rehash of 101 Dalmations with a few minor changes here and there. In fact, it was like watching 101 dalmations all over again. And the reason struck me only later. Most of the scenes were the same as well. The disney company had used footage from the original in this movie also shooting only a few extra scenes to make the movie look different. Does this count as a sequel. Especially when you consider the large sums being spent on the batman and pirates of the caribbean movies. Imagine the plight of those who purchased tickets to watch this so called sequel and rented out the DVD. If someone did a video diff betwen the original and the sequel, I am sure the difference would be not more than 10 or 15%. Such is the amount of reuse. Seriously Disney folks ought to consider refunding my money back.