Is it not correct to use 逗号 (punctuation) in a place where 顿号 should be used? In so many cases I have used 逗号（，） to enumerate a list, which 顿号（、) should be used instead. For example:


  我要去食品杂货店买苹果，香蕉，和西瓜。


However, the correct punctuation should be 顿号:


  我要去食品杂货店买苹果、香蕉、和西瓜。


The reason is just that I could not type in it in my Mac. 

So my questions are:


Is it not correct to use 逗号 to enumerate a list? Or even though it is not correct, nonetheless is it actually used frequently among natives? 
What kind of impressions would I make if I use 逗号 in cases where 顿号 should be used?
Does it have a chance of making a confusion if I use 逗号? In what kind of cases is it acceptable, and in what kind of cases should I refrain from using it?
Technically, 顿号 should be used to punctuate for words enumerating. 

As we all text on computers today, it's more convenient to just type a comma, instead of 顿号. Most of time, it's acceptable nowadays unless some would nitpick. 

In theory, 顿号 would pause shorter than a comma.