what are your thoughts on the cordlessmower last year from Aldi?

I bought a cordlees lawn mower from Aldi last April, after using it 3 times since almost the end of April this year I have experienced a problem on the 1st cut it was cut on high, 2nd one a bit lower and now on the 1st setting. After a short time, the motor seems to race, so I stop for a while and re start, I phoned p and hey would like y machine I for a look into it, what I am concerned about is they will need it or at least 14 days . I do t think tis is very practical, sending it away.
What concerns me also this week they have a new product on sale, which is a different model and battery replacement,which does not fit my machine. What happens when you want to replace the battery. The new model you buy the charger and the battery separate which is a universal battery, the price works out the same as I paid for mine lawn mower with these included and is £24 cheaper than me buying a just a battery for mine.
What do customers think of this cordless machine I bought if they also purchased one .